Cinematographic apparatus



"May 2,1933. s u 1,906,818

0 INEMATOGRAPHI C APPARATUS Fild Jan. 27, 1931 Q 2 Sheets-Sheet 1INVENTbR. 5 z M 1. flwcmm A TTORNEYS.

'May 2, 19 33, F. S EUFERT 1,906,318

CINEMATOGRAPHIC APPARATUS Filed Jan. 27, 1931 2 sums-shat 2 L77 J$WJ6 -wINVEN TOR. W

A TTORNEYS.

' first named modification.

for en the aforementioned cam groove 12". aid means 'may be constructedas follows Fi 2 and so spaced, that always two of said ro ers willtangentiall engage one edge of said cam groove 12" an the othertangentially engage the opposite edge of said groove 12'.

If therefore the cam body 12 is rotated the mirror 26 will slowly movefrom the left hand position dotted lines) to the right hand position(ful line) in 300 of a complete revolution of said body and then quicklyreturn to the initial position in the last The speed of movement of themirror 26 must be exactly equal to the speed of the feed of the film Fso that the projection of the ima e onto the screen throu h the lens Lbe ren ered steady. This spec is controlled by the cam groove 12 and thedriving means therefor.

If desired the shutter 40 may be geared to gear 20 and rotated insynchronism with the other apparatus, being so timed as to cut 01? thelight from lens L during the return movement of the mirror 26 In themodification'shown in Figs. 46 the construction is essentially the sameas in the But in place of a direct coupling between cam 12 and themirror 26 I provide a linkage. Here the cam follower 30, 31, 32, 33which is identical with that of the first named modification, is formedon the end of an arm 34? of adouble armed lever 34. The said lever ispivoted at 34 and the second arm 34 thereof pivotally enga es at 35 alink bar 35. Said link bar pivotally engages a stud 36 provided ondownwardly projecting member 37 attached to the movable mirror 26. Thecam 12 is supported on the shaft 11 rotata'ol borne in a separatecompartment 10 of t e housing 10. Said cam is driven by means of a gear38 and a gear 39 on the sprocket drum shaft 20'.

The principal of operation is the same as, before except that theintermediary linkage between the cam follower and the movablemirrorenables a rearrangement of the elements to eliminateiunnecessary gearingand cheapen the construction without impairing the effectiveness of thedevice.

It is obvious that the mirrors may be. re-

placed by risms if desired.

The in e of operation is as follows If for instance a ray of light Rstrikes the film F at a point z, and is transmitted to the leg 25' ofthe fixed mirror 25 it strikes the latter at :12 and is reflected to theleg 26 striking the latter at w. Thence it is reflected to leg" 26"striking the latter at m and thence to leg 25 striking the latter at 0:and is reflected thereb through lens L onto the screen (not shown If thefilm moves from point a: to point 3 the ray of light that passes throughpoint a: would now pass through point 3 This ray R owing to thesimultaneous displacement of mirror 26 now strikes leg 25 at y isreflected to leg 26 at y, thence to leg 26 at y, thence to leg 26! towhich coincides with 0: so that it will be reflected through the lens Lon same line as before.

It will be seen that this will occur only if the displacement of themirror 26 is in synchronism with the feed of the film so that the imagewill remain stationary despite the motion of the film. r

The chronism is best obtained by rendering ih: displacement of themirrors positive through my novel cam construction and follower means. I

My device may modified in man other ways and I do not wish to be limiteto the details shown and described.

=What I claim is 1. In a cinematographic apparatus having an image feedand equalization means for said image feed, a cylinder having a camgroove for controlling said means, a cam groove follower comprising aset of at least three rollers arranged in triangular fashion on arotatable support and concentrically with respect to the axis ofrotation of said support,- the spacing between said rpllers being soadmeasured that at least two rollers will tangentially bear against oneside of said groove and at least one against the op osite side of saidgroove,said groovebeingso s aped as to control the speed of the movementof said equalization means to'be always equal to the speed of said imagefeed.

2. In a cinematographic apparatus as per claim 1, in which said sup rtfor said rollers comprises a disk rotata' le upon a central axis and isformed with pins 'parallel to said axis and rotatably bearin saidrollers.

In testimony whereof afiix my signature.

FRIEDRICH SEUFERT.

